Exemplary embodiments pertain to the art of environmental control systems and, more particularly, to a method for establishing a set-back temperature for an environmental control system.
Environmental controls have evolved over time from simple temperature based controls to more conventional programmable controls. Programmable controls allow users to set a particular temperature in an environmental control zone for a particular time of day. More specifically, programmable controls or thermostats enable users to program a schedule of temperature set points for a fixed number of time periods over the course of a day. In some cases, a different schedule may be programmed for different days. In many cases, one of the time periods is designated to span a time when the environmental control zone is unoccupied.
As there is no need to maintain a comfortable temperature when the environmental control zone is unoccupied. Accordingly, may users program a lower temperature (for heating) or a higher temperature (for cooling) for the environmental control zone during unoccupied periods. Depending on the lowered temperature, or degree of set back, a user can save on heating/cooling costs. Unfortunately, many users will set too great or too little of a set back. Too great a set back leads to a prolonged recovery time which, in turn leads to the environmental control zone not returning to the comfortable temperature at a desired time and inefficient operation of heating/air conditioning systems. As such, many users do not see any benefit to establishing a set back temperature. Setting too little of a set back also leads to lost savings. That is, a greater savings could potentially be realized with a higher set back. In addition, obtaining optimal savings would require a user to re-program the set back every day as recovery time is related current environmental control zone and outdoor temperature conditions.